Fire-preventing means for motion-picture-projecting machines



ardu 49 E930., T. AL, '19741935577 FIRE PREVENTING MEANS FOR MOTION FICTURE PROJECTING MACHINES Filed Dec, ll, 192 2 Sheets-Sheet l //AJ /l J/ l/9 i y March 4, 930.

FIRE PREVENTING MEANS FOR MOTON PICTURE PROJECTING MACHINES 2 Sheets-Sheet A TTORNEY;

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f means :tor loreahng the Patented Mar. 4, 1930 UNITED THOMAS LEWIS FEENEY AND E'UMBERT GDUY, 'OF PEEIE'LADELHA, PENNSYLVMIUIA,

ASSIGNORS, BY MESNE ASS'GNlViENTS,

llO SAFETY CONTROL CORlPR- TION, OF PHILADELPHIA, PEINNSYLVAM FIRE-PREVENTING MEAltl MEN-EECTURE-'EBQJECTING MACHNES Application filed itecember This invention relates to ineans For the prevention of fire hazards upon the failure of a motion advance a lm subjected to the heat ot an arc light.

The object of the invention is the provision ot means operative responsive to a circuit closing device associated with the motor on the projector whereby the stopping oi the motor will cause said device to remove the source of current from the projector arc circuit.

A feature ot the invention consists in providing for breaking a direct current circuit upon the tailure of a source of alternating current.

Another feature resides in arrangi for the energization ot a circuit closing crevice and the operation of an alternatiu current inotor under the control ot two switching nneans, and tor effectively proventi f" projection of a lilin until looth said swiLdnip,` ineans are in proper position.

A :iurther teature resides in I circuit upon the stopping of the; tor for causes other than the alternating current source These features7 and other a 'l ends which will loe described heh attain in the 'following manner9 ing had to the accornpanyirngy which klligine l illustrates a circuit ir. our invention,

Figure 2 shows a circuit i breaking oi" tlie arc circuit a 'projector naotor :troni ou lolovving ot a in the line therefor7 and Figure 3 another forro rangement adapted to periorni F tion.

Considering Figure 1, nunie ieee.

icture projection mechanism toV Serial o. ELLUQE.

are adapted to he operatively connected loy switches 9 and 10. Generator 11 is provided to supply a source oi direct current to serve any of a plurality oi arcs as 12 and 13 'or projecting a lilin upon a screen. Switches 14tand 15 in the motor generator line ior said arcs? are provided to close the arc D. C. circuit7 and individual switches 16 and 1T provided respectively or arcs 12 and 13 are used to individually connect any ot the arcs as desired. The double set oi switches each projector arc serves as a sateguard, enabling expeditious disconnection oli either arc or the line when the iilni becomes entangled or igor any reason the arc must loe broken to prevent a Relay 18 is provided to control the 4generator circuit and will maintain the circuit closed long.;1 as its winding1 is energlued.

switch 19, coil 20 will loe o the armature oi the relay circuit. Prior to throwrator will usually close n or l depending upon the moving5 when the leat Ls ull intensity., the motor userfl will ere larolren, the i ley the a iine the motor stops7 1 LHS cause7 in order to effec- 'n the exposure o; nono liest ci tile arc.

Figure 2 shows an arrangement in which the arc circuit is broken whenever the motor stops. Numerals 30 and 31 represent A. C. feed lines for motors 32 and 33. Arc 34 is adapted to function with a film controlled by motor 32 and is in circuit with generator 35. A separate generator 36 is provided for arc 37 of the other machine shown. Relay 38 is provided to control the D. C. circuit including generator 35, and relay 39 is provided to control the arc in the other machine. Feed lines in parallel, separately fused, and drawn from lines 30 and 31, serve the machines as shown. The other parts obviously function as in the arrangement of Figure 1 and need not be described.

The arrangements for each machine work identically and hence the one including motor 32, only will be described.

The motor 32 is started by throwing its switch 41 and closing the switch 40 which energizes the relay and closes the generator circuit for arc 34 when the armature of the relay is drawn up to close the same. The arc and film feeding motor are therefore thrown on simultaneously and at this time the dowscr must be kept down over the light projecting aperture. The circuit for the relay is: line 31, motor 32, switch 41, through upper terminal of switch 40, winding of the relay, lower terminal of switch40, the fuse in the line and out to lead 30. In the event the fuse blew out, the motor would stop. Since the relay is in the same circuit, the arc would be broken at the same time. In case the circuit were broken, or a connection either side of the motor came loose, or in the event of a short circuit, the same would hold true. The failure of the motor would be simultaneous with the deenergization of the relay and breaking of the arc. The other machine would not be affected and the performance could go on undisturbed. Since nearly all motion picture theatres have two motor generator sets, this arrangement could be used without necessitating outlay for additonal generator equipment.

In Fi ure 3 a circuit arrangement adapted to function as in Figure 2, is provided, wherein only one generator set is used. Incoming lines 50 and 51 are connected in series with motors 52 and 53. Relays 54 and 55 are provided to operate respectively wit-h motors 52 and 53 and control make and break device 56 which controls the D. C. circuit including generator 57, provided for arcs 58 and 59. Relay 54 has a switch 60 which is adapted to connect the current either to the motor or to shunt it. Relay 55 functions the same way. In operation, where one machine is used at a time the switch of one relay could be in one position and that of the other in the other position. Assuming that the machine including motor 52 were used, switch 60 would be turned to make contact with the left hand terminal. Switch 61 of relay 55 would be turned to make contact with the right hand terminal. Upon closing main switch 62, the circuit path would bc as lollows: lead 51, winding of relay 54, le'it hand terminal of relay 60, motor 52, through relay 55, shunted through right hand terminal of switch 61, upper terminal of switch (52, the winding of relay 56, lower terminal of switch 62, the fuse 63, and out to lead 50. The urina-- ture of rela 56 would pull up and close the arc circuit or arc 58, which would be closed by its individual switches as heretofore explained. The same procedure would hold in operating the other machine. Both machines could be operated at the same time by setting both relay switches to the left. This may be necessary in providing a continuous showing of various reels, where two machines are used. If the fuse 63 blew out, or an other trouble took place in the line, on eit er side of the motor, or in the motor, the armature of rela 54 or of 55 would immediately drop and reak the circuit for device 56, which in turn would break the arc circuit.

It should be noted that either motor in Figures' 2 or 3 could be cut in and the other stopped without breaking thearc circuit. In Figure 3 the momentary throwing of the switch on each relay would not be -suflicient to cause the arc to dull. It is only where the line is broken, not due to the operation of switches 60 or 61 that the relays are designed to drop their armatures. The lag in the relay is not sufficient, however, to delay the breaking of the circuit suflicient to hazard fire from a sustained arc, when the motor stois.

f course, the circuits illustrated may be modified and changed in various ways without departing from the invention herein set forth and hereafter claimed.

We claim:

1. In a mechanism for motion picture projection, a source of alternating current, a motor and a switch for connectin said motor with said source, a make and brea switching device and a second switch for energizing said device in circuit with said source, a direct current generator adapted to be placed in circuit for maintaining an electric arc for projecting a film upon a screen, means operative responsive to said first switch for starting said motor, means including said device operative responsive to said second switch for starting said generator to cause said arc to function, said device being dependent for its energizationupon said two switches and said source of alternating current, said generator being instantaneously inoperative upon the deenergization of said device.

2. In a mechanism for projecting a film upon a screen, a luralit of motors, a plurality of means or pro ucing electric arcs' for projecting lms rotated theifeheoi'e hi? said motors, means operati'veiy connecte With said means for Producing electi-ie arcs for breaking an are circuit upon the 'Eaiini'e of an electric motoi` to continue moi/ing a reel of lm in front of an are and means enabling changing from one motor to anothe Without disturbing the means for pi'odueing and maintaining the electric ares.

In testimony whereof we have signed omD names to this ecification.

THO S LEWIS FEENEL HUMBERT GODOY.. 

